Add suspend-related notifications for CPU hotplug

Since nonboot CPUs are now disabled after tasks and devices have been
frozen and the CPU hotplug infrastructure is used for this purpose, we need
special CPU hotplug notifications that will help the CPU-hotplug-aware
subsystems distinguish normal CPU hotplug events from CPU hotplug events
related to a system-wide suspend or resume operation in progress.  This
patch introduces such notifications and causes them to be used during
suspend and resume transitions.  It also changes all of the
CPU-hotplug-aware subsystems to take these notifications into consideration
(for now they are handled in the same way as the corresponding "normal"
ones).

[oleg@tv-sign.ru: cleanups]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Gautham R Shenoy <ego@in.ibm.com>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/kernel/sched.c b/kernel/sched.c
index fe1a9c2b855a..799d23b4e35d 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -5394,6 +5394,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
                 break;
 
         case CPU_UP_PREPARE:
+        case CPU_UP_PREPARE_FROZEN:
                 p = kthread_create(migration_thread, hcpu, "migration/%d",cpu);
                 if (IS_ERR(p))
                         return NOTIFY_BAD;
@@ -5407,12 +5408,14 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
                 break;
 
         case CPU_ONLINE:
+        case CPU_ONLINE_FROZEN:
                 /* Strictly unneccessary, as first user will wake it. */
                 wake_up_process(cpu_rq(cpu)->migration_thread);
                 break;
 
 #ifdef CONFIG_HOTPLUG_CPU
         case CPU_UP_CANCELED:
+        case CPU_UP_CANCELED_FROZEN:
                 if (!cpu_rq(cpu)->migration_thread)
                         break;
                 /* Unbind it from offline cpu so it can run.  Fall thru. */
@@ -5423,6 +5426,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
                 break;
 
         case CPU_DEAD:
+        case CPU_DEAD_FROZEN:
                 migrate_live_tasks(cpu);
                 rq = cpu_rq(cpu);
                 kthread_stop(rq->migration_thread);
@@ -6912,14 +6916,20 @@ static int update_sched_domains(struct notifier_block *nfb,
 {
         switch (action) {
         case CPU_UP_PREPARE:
+        case CPU_UP_PREPARE_FROZEN:
         case CPU_DOWN_PREPARE:
+        case CPU_DOWN_PREPARE_FROZEN:
                 detach_destroy_domains(&cpu_online_map);
                 return NOTIFY_OK;
 
         case CPU_UP_CANCELED:
+        case CPU_UP_CANCELED_FROZEN:
         case CPU_DOWN_FAILED:
+        case CPU_DOWN_FAILED_FROZEN:
         case CPU_ONLINE:
+        case CPU_ONLINE_FROZEN:
         case CPU_DEAD:
+        case CPU_DEAD_FROZEN:
                 /*
                  * Fall through and re-initialise the domains.
                  */